i am recently start using this pdf bignerd ranch for making app…gladly it says very good

recently i stuck with creation of Action Bar…in the net says need to use Tool Bar instead of Action Bar, which are now deprecated…i used my way…each time i run the app was crashed…it says recently error as like " java.lang.NullPointerException: Attempt to invoke virtual method ‘void android.support.v7.app.ActionBar.setHomeButtonEnabled(boolean)’ on a null object reference " in the CrimeFragment.java file…pls help me what is iam wrong…is this way i want to using…if not pls correct me…i am pasting the code what i used upto now